Reduced Stresses Common Ground Five-Level Boost F-type Inverter with Continuous Input Current

Leakage currents, resulting from common-mode voltages, represent a serious problem in photovoltaic (PV) inverter systems for personnel, equipment, and compliance with grid codes. The common grounded leg-based inverter topology proved to be a viable solution for addressing the leakage current problem. However, existing topologies suffer from the increased number of switches, a high number of passive components, high voltage stresses, and being diode-based, among other issues. The drawbacks become more apparent in the development of multilevel-based CG inverters. Therefore, this paper proposes a new five-level, F-type-based CG inverter for leakage current-free PV inverters. The proposed topology preserves the continuous PV side current and maximizes power extraction from PV systems. The employment of F-type legs enables multilevel diode-free with reduced voltage stresses compared to NPC and T-NPC inverter legs. Furthermore, a predictive control algorithm is proposed in this paper for controlling both the input and output sides with a single objective function, and eliminating the need for a modulator. Simulation results, enhanced with comparative results, are provided in the paper, which demonstrate the superior merits and performance metrics of the new proposed inverter and control method.